The hospital center is a member of the Mount Sinai Health System, a nonprofit hospital system formed by the merger of Continuum Health Partners and the Mount Sinai Medical Center in September 2013. The official names of both hospitals were changed in January 2014 to Mount Sinai St. Luke's and Mount Sinai West as two separate entities. On November 17, 2015 Mount Sinai Roosevelt was changed to Mount Sinai West, but is still known locally as Roosevelt Hospital.

In 1896 it moved to 114th Street. It is across the street, to the east, from Columbia University’s campus and to the South it is flanked by the Cathedral of Saint John the Divine. The historic hospital building at Amsterdam Avenue and 114th Street was designed by prominent socialite architect Ernest Flagg. The chapel of that hospital has stained glass and is the work of the same architect.[2][3]

Woman's Hospital was founded by doctor J. Marion Sims with financial backing from Sarah Platt Doremus, who ultimately became president of the Hospital.[4] From South Carolina, Sims had developed a revolutionary approach to treating vesico-vaginal fistulas, a catastrophic complication from obstructed childbirth. The Hospital was first located in a rented house at Madison Avenue and 29th Street. Dr. Thomas Addis Emmet, who served at the hospital, published the first comprehensive textbook in English on gynecology.[5]

In 1867 Woman's Hospital moved to a new location on Park Avenue, which is now the site of the Waldorf-Astoria Hotel. This had been the burial ground for New York in the 1832 cholera outbreak. 47,000 coffins were dug up to make way for the new construction.[5] In 1906 Woman's Hospital moved to 110th Street and Amsterdam. In 1953 it was merged with St. Luke's Hospital, forming St. Luke's Hospital Center. Finally, in 1965, it was moved to 114th Street and Amsterdam Avenue, just across the street from St. Luke's.[5]

Roosevelt Hospital's first building in opening on November 2, 1871. A plaque to its namesake reads: "To the memory of James Henry Roosevelt, a true son of New York, the generous founder of this hospital, a man upright in his aims, simple in his life, and sublime in his benefaction."

Mount Sinai West is located on 10th Avenue and 59th Street, two blocks west of Columbus Circle. The current 13-story Skidmore, Owings & Merrill designed facility was built in 1990.[6] The original hospital was on the same block but faced Ninth Avenue. Much of the original hospital, including the emergency room, was torn down to make way for two 49-story apartment buildings—One Columbus Place Tower I[7] and II. The oldest remaining component of the hospital is the William J. SymsOperating Theater that had a glass roof built in 1892.[8] It was named for a gun merchant who donated money for it. Its last operation was in 1941 and is now a New York City Landmark. It is still free standing even as the tower surrounds it.[9]

Sinai West Hospital in the forefront of Midtown West and Hell's Kitchen as seen from a rooftop on 59th St.

The Emergency departments at both sites, staffed by 40 physicians board certified in emergency medicine and seven in pediatric emergency medicine, offer 24-hr specialized services for victims of sexual assaults. Both New York City Emergency Rooms have a 24-hour stroke team and Heart Attack (MI) Team. The St. Luke's Emergency Room has a 24-hour on-call cardiac catheterization lab for patients having heart attacks to immediately open up the clogged artery. The Emergency Department hosts a residency in Emergency Medicine with 42 physicians; a fellowship in global health led by Dr. Ramona Sunderwirth and affiliated with the Columbia Mailman School of Public Health; and a fellowship in emergency ultrasound. The Department has two board certified Clinical Toxicologists available for consultation 24 hours. Physicians in the Department are frequently featured on the major local and national television network news programs discussing medical issues affecting the community.

Mount Sinai St. Luke's and Mount Sinai West sponsors 30 accredited residency training programs.[10] The Department of Medicine trains 158 residents and an additional 39 fellows; one of the largest programs in New York State and in the top 10 largest nationally. Each program enjoys full accreditation from the Accreditation Council for Graduate Medical Education and the institution itself is accredited for the maximum 5-year cycle. The Internal Medicine Training Program is one of the most progressive programs in the country utilizing unique strategies to ensure that residents can learn from every patient. These innovations include a "drip system" for distributing admissions and no overnight call anywhere in the training program. In addition, the department limits the number of patients that can be carried by an intern to no more than 11. 83% of the programs in NY, NJ and all of New England still allow interns to carry 12 patients. The program also has its own "Simulation Lab" for training residents. The residency program in Anatomic and Clinical Pathology, is the only one to utilize Mount Sinai Beth Israel in addition to Mount Sinai St. Luke's and Mount Sinai West. Residents have exposure to over 70,000 cases, which cover a wide variety of disease processes, and range from routine to complex and unusual disease entities.

Mount Sinai West's Emergency Room is notable for being the site of John Lennon's death. It was demolished in the early 1980s.

"St. Luke's" is mentioned in the song "Renee" by the Lost Boyz as the hospital where 'Renee' was taken when she was shot and subsequently died.

Jazz saxopohonist Grover Washington, Jr. was taken to St. Luke's-Roosevelt Hospital after he collapsed following a television appearance on December 17, 1999, and was pronounced dead from a massive heart attack.[11]

^Nate Chinen (April 1, 2010). "John Bunch, pianist with Goodman and Bennett, dies at 88". New York Times. Retrieved 2014-12-23. John Bunch, a jazz pianist whose elegant style led to prominent sideman posts with Benny Goodman and Tony Bennett as well as an accomplished solo career, died on Tuesday in Manhattan, where he lived. He was 88. His death, at Roosevelt Hospital, was caused by melanoma, said Cecily Gemmell, his wife and only immediate survivor. ...

^Wolfgang Saxon (1992-06-24). "Rick Sklar, 62, A Dominant Force Behind Rock Radio". New York Times. Retrieved 2008-01-19. Rick Sklar, whose programming made WABC in New York the most popular radio station in North America, died at Roosevelt Hospital in Manhattan on Monday. He was 62 years old and lived in Manhattan. Mr. Sklar died from complications after minor surgery but the exact cause of death is not known, a spokesman from his company said. ...

^"Robert Henri Dies. Ill Eight Months". The New York Times. 13 July 1929. Retrieved 13 April 2015. Robert Henri, eminent American artist, died early yesterday morning at St. Luke's Hospital. Although he had been a patient at the institution since November, his illness was not generally known and his death came as a surprise to art circles. ...